Variable speed gearing, particularly for motor vehicles



12, 1932. v v TT 1,854,082

VARIABLE SPEED GEARING, PARTICULARLY FOR MOTOR YEHICLES Original FiledNov. 19, 1929 16 I 15 U: H 56 19 1 1 G 1a ug J80. aa-

51 a5 52 I I l I r u 5 10 9 3o 29 27 28 Patented Apr. 12, 1932 UNITEDSTATE-s VITTORIO vALnE'rrn, or 1 1mm,, ITALY, nssrononf'ro FIAT SOOIETAANONIMA,

'runm, ITALY c 'i QFFM' vARIABLEsrnnn Gamma, PARTICULARLY ron MOTORVEHICLES Original application filed m her 1-9, 1929', semi No. 408,292,and in Italy November 24, 1928. Divided and this application filedSeptember 18, 1930. Serial No. 482,839.

This invention refers toa change-speed gear forfmotor vehicles;comprising sets of internally toothed Wheels of the type described inthe copending patent application, Ser. No.

351,971 and is a division of my Patent,

1,796,067, granted March 10, 1921. The object of this invention is tosimplify the construction from the standpoint of manufacture andmounting, without altering the size of the members of the mechanism.

Another object of my invention is to strengthen the annular support forthe internally and externally toothed gear in order to improve therigidity of mesh of said gear.

Other objects and advantages ofmy inven: tion will be set forth inthefollowing specification, in which reference is made to theaccompanying drawing which is an axial vertical section through avariable speed gearing of the type specified, wherein the annularsupport for the C-shaped ring is made shorter and continuous, and thetoothed wheel transmitting motion from the engine shaft to thegounter-shaft is arranged outside the gear Referring to the drawing 1denotes the gear box through which are fitted the engine shaft 2 and thebell-shaped end of the transmission shaft 22.

The engine shaft 2 drives a C-shaped ring 8 having an internal set ofteeth 7 meshing with the pinion 6 of the engine shaft and an externalset of teeth 9 meshing with the internal I set of teeth 10 of the crown11 carried by the sleeve 12 mounted on the engine shaft 2 by means of abush bearing 13.

The C-shaped ring 8 is supported by an annular flange 14: excentricallyprojecting from the member 16 fixed to the front wall of the gear box 1and coaxial with the engine shaft, said member housing the ball bearing17 for the engine shaft 2. A set of rollers 15 are inserted between theC-shaped ring 8 and the annular flange end placed in the hollow of theC-shaped ring in the same plane as the sets of teeth 7 and 9.

The annular support 1116 is very short and requires no gap, throughwhich the toothed wheels transmitting motion from the engine shaft tothe counter-shaft may engage,,while such a gap was required in theconstruction according to the copending application. 1 k V The toothedwheel 5 keyed on the countershaft-3-issituated outsidethe gear box 1 andmeshes with a toothed wheel keyed on a portion of the engine shaft 2external to the gearbox. The wheels 4. and 5 are protected by the cover36. v

The transmission shaft 22 carries a single bell .20 housing the bushbearing 23 in the sameplane as the roller bearing 86 mounted in the rearWall of'the'gear box 1 and supporting in the usual manner thetransmission shaft 22. A bush bearing 2Lis arranged \Vlthlll a sleeve 19capable of axial displacement, but kept against rotation within the bell20. Said sleeve 19 is provided with dog teeth 19a adaptedto alternatelyengage the teeth 12a. and 184;, respectively, of the sleeve 12 and crown18 of the engine shaft 2; the dog teeth 19a-of the sleeve 19 being twiceas high as the teeth 12a and 18a, because it .is necessaryfrom aconstructional standpoint tomake the sleeve 12 with an innerdiameterequal to or larger than thatof the set of teeth 18a.

. For the same reason the bush bearingl3 is diametrically subdividedinto two parts which are secured by screws 13a to the sleeve 12 and holdthis latter against a shoulder on the shaft 2.

The sleeve 19 is slidably keyed to the bell 20'by means of teeth 206 onthe bell engaging grooves 19?) on the sleeve. V

The bell-shaped end of the transmission shaft is provided with toothedcrowns 28 and 30 with'which may alternatively engage the pinions 27 and29 respectively, said pinions being rigidly connected together andmount-- edon the counter-shaft 3 for axial displace ment by means of theusual collar 31.

*The counter-shaft 3 is supportedin the usual manner by the front andrear wall of'the'casingl through ball bearings 32 and 33 respectively.

r The working of the above described va 7 riable speed gearing is asfollows; supposingv the partsin .theidler position as shown in thedirawing,I movethe slidable pinions on the counter-shaft 3 to right handuntil the pinion 27 engages the toothed crown 28 and obtain the firstspeed, then displace the slidable pinions to left hand for engaging thepinion 29 with the toothed crown 30 and obtain the second speed. For thethird speed I bring the slidable pinions in idler position and displacethe sleeve 19 to left hand until the teeth 19a engage the teeth 12d; thedirect drive is obtained by bringing the teeth 19a of the sleeve 19 inmesh with the teeth 18a on the engine shaft.

What I claim is:

1. Variable speed gearing comprising, in combination with a box, adriving shaft and a driven shaft mounted in said box, one end of saiddriven shaft being in the shape of a bell, in which the driving shaft isco-aX- ially supported, an annular member traversed by the driving shaftand secured to the box excentrically with respect to said shafts, aC-shaped ring supported by said excentric annular member and having aninner set of teeth and an outer set of teeth, a pinion keyed on thedriving shaft meshing with said internal set of teeth, a sleeve looselymounted on said driving shaft, a set of internal teeth fast with saidsleeve and meshing with said external set of teeth of the C-shaped ring,dog teeth on said sleeve and on said engine shaft, a sleeve movable inthe bell-shaped end of the transmission shaft and provided with dogteeth that may be alternatively brought into gear with the dog teeth ofthe first mentioned sleeve and of said engine shaft, two toothed crownson said bell, a counter-shaft, a toothed wheel on said countershaftmeshing with a toothed wheel on the engine shaft arranged externally ofsaid annular excentric member and pinions mounted for axial displacementbut kept against rotation on said countershaft and that may bealternatively thrown into gear with the corresponding toothed crowns onsaid bell.

2. Variable speed gearing comprising, in combination with a box, adriving shaft and a driven shaft mounted in said box, one end of saiddriven shaft being in the shape of a bell, in which the driving shaft isco-axially supported, an annular member traversed by the driving shaftand secured to the box excentrically with respect to said shafts, aC-shaped ring, supported by said excentric annular member and having aninner set of teeth and an outer set of teeth, a pinion keyed on thedriving shaft meshing. with said internal set of teeth, a sleeve looselymounted on said driving shaft, a set of internal teeth fast with saidsleeve and meshing with said external set of teeth of the C-shaped ring,dog teeth on said sleeve and on said engine shaft, a sleeve movable inthe bell shaped end of the transmission shaft and provided with dogteeth that may be alternatively brought into gear with the dog teeth ofthe first mentioned sleeve and of said engine shaft, two toothed crownson the bell, a counter-shaft, a toothed wheel on an ex tension of saidcounter-shaft external to the gear box, a toothed wheel on the engineshaft externally of the gear box and meshing with the toothed wheel onthe counter-shaft, a casing for protecting said toothed wheel fixed .tothe gear box and pinions mounted for ex ia-l displacement but keptagainst rotation on said countershaft'and that may be alternativelythrown into gear with the corresponding crowns on said bell.

In testimony that I claim the foregoing as my invention, I have signedmy name. VITTORIO VALLETTA.

